Dispersed hypothalamic cells have been cultured to study humoral interactions with neuropeptide secretion. The interpretation of results from these studies is complex since numerous neuronal and non-neuronal cell types are present in these cultures. Thus exogenous modification of the humoral environment may affect neuropeptide secretion directly and/or indirectly. The preliminary data in this proposal demonstrates that sepharose-linked recognition complexes may be used to separate luteinizing hormone releasing hormone (LRF) neurons from dispersed hypothalamic cells. Further, the methods employed yield a remarkably undamaged LRF neuronal population. I propose to utilize LRF neuronal cultures to study direct effectors of LRF synthesis and release. One or more of the following criteria will be judged as an indication of direct humoral interaction with isolated LRF neurons: (a) ability to produce an effect upon the radioimmunoassayable (RIA) media concentration of LRF, (b) capacity to reduce or enhance potassium-induced release of LRF into the culture media, (c) ability to increase or decrease the rate of incorporation of radiolabeled amino acids into the LRF molecule and (d) co-localization of effectors in or on the LRF neuron by immunocytochemistry or linkage of effectors with tracer molecules. These studies will provide important neuroendocrine data on the control of LRF secretion by identifying humoral substances which may directly affect the biosynthetic and/or neurosecretory activity of isolated LRF neurons.